A marine glider has become the first craft of its kind to cross the Atlantic. Released off the coast of the USA and recovered last week off the coast of Spain, the ‘Scarlet Knight’ took 221 days to cover 7,389 kilometres.

Such gliders are already widely used in oceanography but this new feat of endurance could lead to a huge increase in their abilty to gather data on ocean processes and climate change.

“They swim like dolphins. We can put them into storms and places not safe for human beings,” Scott Glenn, of Rutgers University in New Jersey, told the Guardian just before the craft was recovered.

“The vision is of omnipresence, of being able to be all over the ocean by having lots of inexpensive robots tweeting back messages.”

The glider changes it density in order to rise or sink, and its wings turn this up and down movement into a forward glide. The Scarlet Knight – which is yellow and not scarlet – has some barnacles and other marine gunk growing on it. But, says researcher Tina Haskins, “she is still mostly yellow”.

Image: Rutgers